Using Enumeration District Maps

The key to finding your ancestor in the 1940 census is determining which enumeration district (E.D.) they lived in. In cities, enumeration districts could encompass a few city blocks, while in rural locations a district could cover a much larger area. has posted enumeration district maps that outline these districts and can be very useful in locating your ancestors in the 1940 U.S. federal census.

To begin, plot your ancestor’s address on a contemporary map by typing the address into a search engine. In some cases street numbering may have changed over the years, but in most cases, this will get you in the ballpark.

Jot down cross streets and surrounding streets and look for features like lakes or rivers, diagonal streets, railroads, parks, cemeteries, and other landmarks. This will help you locate the street on the enumeration district map. (Keep in mind that some aspects of the neighborhood may have changed. That shopping center on the contemporary map, may have once been a sub-division, so try to find things that would have stood the test of time.)

Once you’ve become familiar with your ancestor’s immediate surroundings, widen the zoom to determine what portion of the city you’re looking at. Since the maps for some cities were scanned in quadrants or even smaller pieces, this can help zero in on the map image your portion of the city falls in.

Now you’re ready to take a look at enumeration district maps. Use the browse drop-downs on the right, and navigate to the map you need.

In some cases, you’ll find the location all on one map, but in other cases you may have to browse through a few to get to the map you need. Note the edges of the map as you browse the images to determine whether you’re in the north, south, east, or west sections of the map and look for those landmarks you noted in the contemporary map. Knowing the general direction you need to find can help you jump ahead to the section you need.

Once you’ve identified the location on a map, look for a hyphenated number that is the enumeration district number. The boundaries of the district are typically outlined, as below.

Now that you have a number, it’s time to start browsing 1940 census records. Using the Standard Browse, select your ancestor’s location, and you get to the local level, look for that enumeration district number. Now you can start browsing those images for your family. If you look along the left side of the census forms, you’ll see the street names. From the green Actions button in the upper right corner of the image viewer, you can select image options and then rotate the image left. Now you can fly through the images looking at street names without getting a crick in your neck. When you come to your ancestor’s entry, just select the option to rotate right to flip it back.